Satellite Passes

About Satellite Passes

Satellite Passes is an API that predicts upcoming passes of a given satellite over a specified location. It accepts a NORAD ID along with latitude and longitude, and returns pass data including rise, culmination, and set times with altitude and azimuth values. It uses Skyfield for pass prediction and pulls updated TLE data from the Celestrak GP API.

The API supports optional parameters to limit the number of results, set how many days ahead to calculate, and filter for passes that are likely visible to an observer, based on the satellite being sunlit while the observer is in darkness near the horizon. Each response also indicates whether the satellite is sunlit at each point in the pass. Results are cached for one day per parameter combination, except when the limit parameter is varied.

This is aimed at developers building applications involving satellite tracking or visibility prediction, such as tools for observing objects like the ISS from a given location. Source code, documentation, and an OpenAPI specification are available.

Key features

• Predicts upcoming satellite passes for a given latitude/longitude using Skyfield
• Fetches updated TLE data from the Celestrak GP API
• Filter results to visible-only passes with the visible_only parameter
• Limit results by number of passes or number of days ahead
• Returns rise, culmination, and set details including altitude, azimuth, and sunlit/visibility status

Frequently asked questions